Full synchronized distributed array antenna for CDMA base stations

Adaptive array antenna is one of the attractive technologies for cellular mobile communications systems for increase of capacity. For CDMA cellular base stations, we have designed a distributed configuration of array antenna, which is synchronized among two-dimensional arrange of sub-array antenna modules. This configuration has a capacity to accept flexible number of or arrange of sub-array antenna modules. All modules that formed array antenna are synchronized to make appropriate beam forming by the method of one-by-one addition between each adjacent module. We have built a prototype of this distributed array antenna with our original continuous auto-calibration circuits. The experimental performance of this calibration circuit was 0.1 dB and 1-degree accuracy. The prototype array antenna has experimentally performed less than 2 dB ripple and 11.3-degree roll-off (between -3 dB point and -20 dB point) of sector wide beams and 12.7-degree beam width (-3 dB) of user dedicated narrow beams.